Geothermal Heating

A geothermal heating system uses the virtually constant temperature of the earth to warm or cool buildings. The system consists of piping underground in a series of loops. A heat pump in the building connects to the loop system. In a geothermal system, when you need to get heat into the building, the heat pump pulls it from the ground loops. In a geothermal system, when you need to get heat into the building, the heat pump pulls it from the ground loops. When the pump pushes that heat up into the building, it sends the heat from huge subterranean spaces not too far away from the loops themselves, meaning the heat pump doesn't have to work nearly as hard.

An Earth-coupled heat pump utilizes the underground earth as a heat source in the winter and a heat sink in the summer. When the system needs to provide heating, it removes heat from the ground and puts it into the structure being heated. During the cooling season, the heat pump takes heat from inside the structure and puts it into the ground. The system must be able to use nearly the same amount of energy as the efficient electric motor that drives the system. Overall, the geothermal heat pump has a negative impact on the environment because of the mining and drilling operations, which are a net carbon sink.

Compared to conventional heating, ventilation, and air conditioning systems, geothermal systems usually carry much higher upfront costs. Installation can set a homeowner back anywhere from $10,000 to $25,000, depending on the home's size and the conditions found underground. Yet many homeowners find that they recoup their costs in just a few years through substantial energy savings. And a number of local and federal programs offer tax credits and other incentives that can bring the net costs down significantly.

Geothermal heating systems are highly efficient, performing at levels 300% to 600% better than conventional heating systems. For every unit of electricity that geothermal systems use, they generate three to six times as much heating or cooling energy. The underground temperatures allow for stable and reliable geothermal system performance year-round. These high efficiency levels yield substantial energy cost savings for homeowners.

The four main kinds of geothermal ground loop systems are horizontal, vertical, pond/lake, and open loop. For residential properties, horizontal loops are the most common. These systems have enough space to 'spread out' their piping, with loops typically placed 6 to 8 feet deep in the ground. When dealing with either limited space or challenging soil conditions, vertical ground loop systems can be a more effective way to access geothermal energy. These systems generally use fewer, but longer, pipes and can place them deeper into the earth, where conditions are more stable.

Nearly all climates can use geothermal heating effectively because the temperature just a few feet underground remains relatively stable, even in the hottest or coldest regions. Standard setup and operation of a ground-source heat pump is, however, contingent on the local underground geology and the climate aboveground. When you hear geothermal in the context of a heating and cooling system, it's almost always a ground-source heat pump that's being referred to.

Compared to traditional heating, ventilation, and air conditioning (HVAC) systems, geothermal systems require much less maintenance. Ground loops are generally guaranteed for 50 years and can last much longer with proper installation. Regular professional inspections help ensure the system runs as it should and allows any potential problems to be identified early, before they can really cost homeowners much in terms of money or inconvenience. In between these annual sessions, it is mainly the homeowners' responsibility to check and replace air filters and keep the various components of the heat pump clean and in working order.

Heating with geothermal energy has a greatly reduced carbon footprint, and it does not rely on fossil fuels. Instead, geothermal heating uses renewable energy from the earth, producing negligible amounts of gases that contribute to greenhouse warming. Because geothermal systems use less electricity, they significantly reduce environmental impacts across the board. International environmental experts frequently list geothermal heating as a strategy that can aid the transition to an ecologically sustainable energy infrastructure.

The typical lifespan of a geothermal heat pump is 20 to 25 years, which is significantly longer than that of traditional HVAC systems. With proper installation and workmanlike quality, the ground heat exchanger (or ground loop) should last 50 years or more. Geothermal heat pumps seldom need repairs, and if they do, it's usually minor work on the indoor components (the "wet end") of the system. No one's studied the cost of maintaining a geothermal heat pump over the long haul, but there’s every reason to think that this class of system is as "low maintenance" as a unit gets.

You can apply geothermal heating in buildings of all sizes, from tiny residential structures to large commercial properties. How you might set up the system depends on everything from the property size and the conditions of the soil to the actual demands of the property for heat and air. A small building might use a compact, vertical-loop system; a large building might have its extensive horizontal loops. No matter the property you're working in, some kind of professional assessment is needed to determine which of Earth's many geothermal configurations is most appropriate for the property's unique circumstances.